1. Field
The present inventive concept relates to a liquid crystal display device and, more particularly, to a liquid crystal display device capable of maintaining the reliability even if temperature and/or humidity changes.
2. Description of the Related Art
With the trend towards thin, light weight portable display devices, e.g., a laptop, a mobile phone, a portable media player, and so forth, as well as household display devices such as televisions, monitors, and so forth, various flat panel display devices are widely used. Flat panel display devices include a display panel for displaying an image, and may be classified into a liquid crystal display device, an organic light-emitting display device, an electrophoretic display device, and the like, depending on the type of the display panel.
The liquid crystal display device may include a liquid crystal panel containing a liquid crystal layer and a polarizing plate. The polarizing plate may be disposed on the upper surface and the lower surface of the liquid crystal panel. The liquid crystal display device can control the movement of liquid crystal particles included in the liquid crystal layer, thereby controlling the state of polarization of light transmitted through the liquid crystal layer. The liquid crystal display device can control the transmittance of light transmitted through the liquid crystal layer by controlling the state of polarization of light transmitted through the liquid crystal layer, thereby displaying an image.
Since the liquid crystal panel cannot emit light on its own, the liquid crystal display device may further include a light source for generating light, a light guide plate for uniformly dispersing the light emitted from the light source to provide the light the liquid crystal panel, and an optical sheet for controlling the optical properties of light emitted from the light guide plate.
The optical sheet and the polarizing plate may be disposed between the light guide plate and the liquid crystal panel. The optical sheet and the polarizing plate may be disposed adjacent to each other. The optical sheet and the polarizing plate may be directly or indirectly connected to each other. The optical sheet and the polarizing plate may expand or contract according to changes in temperature and/or humidity. The deformation, i.e., an expansion rate or contraction rate, of the optical sheet may be different from that of the polarizing plate. If the expansion rate or contraction rate of the optical sheet is different from that of the polarizing plate, and the optical sheet and the polarizing plate are directly or indirectly connected to each other, the contraction or expansion of the optical sheet or polarizing plate may cause a deformation of the other one. For example, the optical sheet may be wrinkled due to the contraction or expansion of the polarizing plate. If the optical sheet or polarizing plate is deformed, the display quality of the liquid crystal display device may be reduced.